Woven ladder webbing



Sept 2, 1952 G. F. FRENCH ET AL wovEN LADDER WEBBING Filed Nov. 1, 195o #www -MHHWHH .MUIVIL WMU. \1, d; HI ,..HHW Hwj .IIHHI/ if IIIIIIIIIIII/ .f. UML h y, W/,w1 h, u., r HL. ffnu||||1|w,%\l 1 (VII. l F.M... MNHN. ..ll.. U WHMHWHMTNIQ! rrnuuunumuwM/IJMW. h .1L df 11m am 11% Patented Sept. 2, 1952 UNITED vSTATES Param oFFiCE'- George Frederick French and RogerFrench, Y v Manchester, England Application November 1, 195o; serial No. wager ln Greatiritain November 1, 1949 This invention relates to the manufacture of woven ladder webbing, that is to say any webbing consisting of at least two main webs between whichl are located cross straps secured-to or bound-in" to any two adjacent main or body webs by and in the operation of weaving of the said Webs.

Woven ladder webbing as above dened has been known for very many years and in a large number of varieties. particularly as regards the number of the main or body webs, the number and relative disposition of the cross straps, the manner of securing or binding-in of such cross straps to the main or body webs, and the nature of the cross straps. For example, while a ladder web has usually only two main or body webs, ladder web is known having three body webs and it would not be impossible to increase that number. Again, the number and relative disposition of the cross straps have varied greatly while the nature of the cross straps has included such variations as the use of warp elements, such as cords, tapes, and groups of unwoven warp threads, as distinct from the original woven cross tapes, Woven during the weaving of the main or body webs.

It has been. until the present invention, the practice to have a weaving cycle in which, taking for example any one cross strap between two adjacent body webs, the cross-strap-forming warp threads are bound into one body web, and then, after a weaving period, during which both the body webs, and the warps of the cross strap also, are woven for a length equal to the required length of the cross strap, such warp-like crossstrap-forming warp threads are then bound into the other body web, the cycle being completed by carrying the cross-strap-forming warps back to the first web leaving between the body webs a short cross-over portion thereof. Such short cross-over portions of the warp threads hold the body webs in a relatively unseparable position, and must be cut to enable the web to open to its aptly described ladder form. The two outer webs are. by such method, woven as close together as possible. one over the other, so that at the beat up there is just space between them for the thickness of the cross straps. The same procedure has always been followed as regards the sequence of securing or binding-in, though sometimes the warps of the cross straps are left weftless. or cords or tapes or other warp-like crossstrap-forming members are used in place of such warps.

The cross straps are therefore formed only by warp ends at each alternate cross-over of the 2 claims,v (c1. 13e- 7384) cross-strap-forming members between-the body webs, the intermediate shortcross-over portions beingsevered.

-1 In fact, whatever the kindor'species ofwoven ladder web having l.warp-likev cross straps it has hitherto been preconceived as a fundamental necessity that there must be formed during weaving such short cross-over portions of the cross strap warps or their equivalent, and that there must be a cutting operation therefor.

The aforesaid proximity of the main webs during weaving is obviously dictated by conditions for obtaining effective shedding for simultaneous weaving of the cross straps and to keep the said short free portions as short as possible so that the ends left after cutting are not so long as to require trimming.

The present invention is based upon an appreciation that such preconception is erroneous, and that the said short cross-over portions and cutting operations are both avoidable.

According to the invention a ladder web including two woven body webs is characterised by longitudinal continuous warp elements crossing between the two body webs to provide cross straps at each cross-over and bound into one of the body webs between successive cross straps.

The drawing illustrates in a perspective view the preferred construction of a ladder web in accordance with this invention.

As shown in the drawing the ladder web consists of body webs e and ,f with four sets of warp threads respectively g, h, z' and y', of which g and h are shown in chain line. Each cross strap is therefore composed of warps g and i or h and :i which cross zig-zag between the body webs but in opposite directions and are bound in to each web respectively at g', h', z" and y". In this arrangement the number of warps shed for the main webs remains substantially constant throughout their length. as for example, considering the body web e, when the warp threads g and h leave it to cross to the other body web f they are almost immediately replaced by the other warps i and i respectively crossing in the opposite direction from the other body web f.

In producing the ladder web illustrated, the cross strap warp threads y, h, i and 7' are first woven integral with the body webs for a predetermined distance or number of picks; for example, g and h are woven integral with the body web e at g and h' and i and i are woven integral with body web f at i' and y". Then the cross strap warp threads y and h are taken across after the last securing or binding-in pick of body web e to the rst securing or binding-in pick of the body web f. Likewise the cross strap warp threads i and y' are taken across after the last securing or bind-in pick of body web f to the rst securing or binding-in pick of the body web e. Warp threads y and h are then woven integral with body web f for a predetermined distance and Warp threads z' and 7 are woven integral with body web e for a like predetermined distance. This procedure is then continuously repeated to form a completed ladder web.

As is easily appreciable in the nished ladder web according to the invention the cross strap warp threads or other warp elementsv are. continuous throughout the length of the webbing` and in zig-zag relation to the main webs. Also., the invention is applicable to any convenient a1:-- rangement of cross straps.

The elimination of the cutting operation reduces the cost of production and also a common cause of production loss. f

What we claim is:

1. In a ladder web construction including two bedyfwebscross straps formed by two setsoffcontinuous .Warp threads.; bound-in alternately: into Ithe said main body webs and crossing between them to form the straps, the binding-in of the warps of one set alternating in each body web with the binding-in of the other set.

l2. In a, ladder web according to claim l, pairs of side-by-side cross straps.

GEORGE FREDERICK FRENCH. ROGER FRENCH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Germany June '7, 1910 

